What is Triple DES?
Q: What is Triple DES?
A: Triple DES (TDES or TDEA) is a block cipher created from the Data Encryption Standard (DES) cipher by using it three times. It was designed to increase the key space and prevent meet-in-the-middle attacks that are effective against double DES encryption.
Q: How long is the key length of 3-key TDES?
A: The key length of 3-key TDES is 168 bits, with three 56-bit DES keys and parity bits for a total storage length of 192 bits.
Q: How long is the key length of 2-key TDES?
A: The key length of 2-key TDES is 112 bits, with two 56-bit DES keys and parity bits for a total storage length of 128 bits.
Q: What type of attack can be used against 2TDES?
A: 2TDES can be taken advantage of through certain chosen-plaintext or known-plaintext attacks. As such, it is treated by NIST to have only 80 bits of security.
Q: Is Triple DES better suited for software or hardware implementations?
A: By design, Triple DES suffers from slow performance in software so it is better suited to hardware implementations.
Q: Is Triple DES still widely used today?
A: While Triple DES has largely been replaced by Advanced Encryption Standard (AES), it remains an active cryptographic standard within the electronic payments industry where it continues to develop and spread standards based upon it.
Q: What does EMV stand for in relation to Triple DES?
A: EMV stands for Europay Mastercard Visa which is a standard for interoperation between IC cards ("Chip cards") and IC capable POS terminals and ATM's that uses 2TDES extensively.
